In the past, there have been axial-flow fans in which a boss and a plurality of blades are integrally resin-molded with a hub, an axial hole through which a drive motor shaft is inserted being formed in the boss in the axial center of the hub, such as those shown in Japanese Laid-open Patent Application No. H5-340383 and Japanese Laid-open Patent Application No. 2011-74817. The hub herein has an outer perimeter cylinder and a lid. The outer perimeter cylinder is a portion having an opening in the axial center, a plurality of blades being formed so as to project from the outer perimeter edge. The lid, which extends from the outer perimeter cylinder toward the boss so as to cover the opening of the outer perimeter cylinder, is a portion for connecting the boss and the outer perimeter cylinder together. Specifically, the boss is connected to the outer perimeter cylinder and integrated with the hub by the lid. Reinforcing ribs are also formed between the hub and the boss.